Demographic.. They are really well built and the materials are thick and solid. They will last 10 years without maintanance according to the bloke, so he wasn't bothered about the price as he will nearly double his money in the first year if he can fill it every night. Realistically though he will at least make his money back.
Of that I have no doubt, I work as a carpenter though and even considering the spec listed HERE I would have thought there is a decent profit margain for the people who make and build them as long as they don't doss about whilst making them.
I am not saying that they are no good at all, I love the look and would have to say the specifications are good, the only thing I would say is that the company making them should do well in business.
But the campsite can make the money back as well so everyone is happy.